It takes an object 2 minutes to speed up from 67 m/s to 528 m/s the acceleration is

Average acceleration = (change of speed) / (time for the change)

change of speed = (528 m/s - 67 m/s) = 461 m/s

time for the change = 120 seconds

Average acceleration = (461 m/s) / (120 sec)

Average acceleration = 3.842 m/s²